Frequency Reconfigurable Split Ring Antenna for LTE And WiMAX Applications

This paper presents frequency reconfigurable dual band antenna for WiMAX and LTE 2500 band applications using four PIN diode switches. The antenna is compact in size with dimensions of 30 x 30 x 0.8 mm3 and designed on FR-4 dielectric substrate with a partial ground plane. The fabricated antenna operates in the frequency range of LTE and WiMAX (2.5-2.69 GHz and 3.4-3.6 GHz) respectively.  The frequencies can be controlled by using PIN diodes and antenna attained the gain ranging of 3.34-4.46 dBi. This designed antenna resonating at 2.52 and 3.49 GHz when the PIN diodes are in ON state and resonating at 2.68 and 3.58 GHz when PIN diodes are in OFF state. The proposed antenna has bidirectional radiation at upper frequency bands and unidirectional at lower frequency bands. The proposed split ring structured antenna has the radiation efficiency of 94.12% at 2.52 GHz and 90.34% at 3.49 GHz in ON state. Antenna providing good agreement between the measured (Antenna measurement setup with VNA) and simulated results (Ansys-HFSS)

Synthesis, Characterization and Phase Transition Studies on Some N-(4-Butyloxy Benzylidene)-4-Alkoxy Anilines, 4O.Om Compounds - A Dilatometric Study

Dilatometric studies are carried out on the synthesized N-(4-butyloxy benzylidene)-4-alkoxy anilines, 4O.Om compounds with the m = 3 to 7 and 9. Characterization of these compounds is done using the polarizing microscope attached with a hot stage. The differential scanning calorimeter is employed to find out the transition temperatures as well as the heats of transitions. All the compounds exhibit nematic phase with varying thermal ranges with the clearing temperatures are above 100 OC as unlike the case of the well known N-(4-butyloxy benzylidene)-4-alkyl anilines, 4O.m compounds which exhibit rich poymorphysim and the clearing temperatures are well below 100 OC. As expected the isotropic to nematic transition exhibited first order nature and the results are discussed with the body of the data available in literature

Design of Microstrip Patch Antenna Based on FSS for 5G and Wimax Applications

This work offers an optimized microstrip patch antenna for 5G and Wi-Max applications. The proposed design is based on rectangular patch antenna embedded with frequency selective surface consisting of an array of 4 x 4 patches to increase the gain of the antenna by more than 7dB. FSS layer is mounted under the microstrip patch of the antenna which provides a stop band response with more than -60 dB loss at the frequency range 3.5 GHz and more than 30 dB at 6 GHz

Soil Amendments for Sustainable Intensification

Maintaining proper soil health is one essential element of sustainable agriculture and safeguarding ecosystem services. Beyond rendering provisioning services like food, fiber and fuel supply, soils play a critical role in services like climate regulation, water quality and supply regulation through soil functions of regulation of greenhouse gas (GHGs) emissions, filtration/buffering of substances in water, water infiltration and water flow in soil, etc. (FAO and ITPS 2015). Supporting cultural services and soil functions like nutrient cycling, soil formation, medium for seed/root growth and natural and cultural landscape diversity also depends on the state of soil health..

Balanced nutrient management: Effects on plant zinc

Participatory on-farm research on the diagnosis and management of nutrient disorders over the last decade by the International Crops Research Institute for the Semi- Arid Tropics (ICRISAT) and its partners has established that multi-nutrient deficiency is the norm rather than an exception. The results of analysis of a large number of soil samples from farmers’ fields in the semi-arid tropical regions of India showed that generally the soils are low in organic carbon (C), indicating general poor soil health. Apart from deficiencies of the major nutrients nitrogen (N) and phosphorus (P), the deficiencies of secondary nutrient sulfur (S) and micronutrients especially zinc (Zn) and boron (B) are widespread and indeed revealing. The results from a large number of on-farm follow-up trials comparing soil test-based balanced nutrition with farmers’ inputs showed that balanced plant nutrient management significantly increases crop productivity (Sahrawat and Wani 2013) and enhances grain and straw quality of crops (Sahrawat et al. 2008). Currently..

Stretching Soil Sampling to Watershed: Evaluation of Soil‐Test Parameters in a Semi‐arid Tropical Watershed

Soil sampling is an integral component of fertility evaluation and nutrient recommendation for efficient use of nutrients in crop production. Little attention has been devoted to evaluating methodology for sampling watersheds under dryland agriculture. A stratified random sampling methodology for sampling the Appayapally watershed in Mahabubnagar district of Andhra Pradesh state in the semi‐arid tropical region of India was adopted and evaluated. The watershed has an area of about 500 ha, with gentle sloping lands (<1% slope), and 217 farmers own land in the watershed. The soils are Alfisols. A total of 114 soil samples were collected from the top 15‐cm layer to represent the entire watershed. Each sample was a composite of 7–8 cores, randomly collected from the area represented by a crop and group of farmers. The soil samples were air dried, ground, and analyzed for pH, electrical conductivity (EC), organic carbon (C), total nitrogen (N), and extractable phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), sulfur (S), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), and boron (B). Statistical analysis of the results on soil fertility parameters showed that the mean‐ or median‐based results of soil tests performed in the study did not differ significantly when the sample set size varied from 5 to 114 (100% of the population). Our results indicate that farmers' fields in the Appayapally watershed are uniform in the chemical fertility parameters studied, and even a small sample set size can represent the whole population. However, such a sampling strategy may be applicable only to watersheds that are very gently sloping and where fertilizer use is very low, resulting in an overall low fertility in the whole watershed

Macro-benefits from boron, zinc and sulfur application in Indian SAT: a step for grey to green revolution in agriculture. Global Theme on Agroecosystems Report no. 16

The semi-arid tropics (SAT), spread over 11.6 million KM square worldwide, is home to millions of poor people. The soils are low in fertility and degraded to varying extent. The climate is characterized by undependable rainfall, high average temperature and water stress situations for crop growth. The SAT is densely populated and a large number of poor in this region depend on agriculture. The green revolution in Asia bypassed the large tracts of rainfed systems. ICRISAT is committed to improve livelihoods of millions of poor living in the SAT by undertaking agricultural research for impact in a partnership mode. The new watershed model emphasize the management of water as an entry point for improving livelihoods through convergence of natural resource-based activities. ICRISAT's on-farm community watershed research in Asia revealed that the SAT's subsistence agricultural systems have soils depleted not only in macronutrients but also in micronutrients such as zinc and boron, and secondary nutrients like sulfur beyond the critical limits. Widespread (80-100%) deficiencies of micro and secondary nutrients were observed in farmers' field in Andhra Pradesh, India. Substantial increase in yields by 20 to 80% due to micronutrient amendments, and a further increase by 70 to 120% due to micronutrients and adequate nitrogen (N) and phosphorus (P) amendments in a number of crops (maize, sorghum, mung bean, pigeonpea, castor, chickpea) in farmers' fields were observed. Besides minimizing land degradation, increased use efficiency of the inputs such as N and P fertilizers, as well as rainwater, resulted in increased profits and increased productivity. These natural resource management (NRM) interventions are integrated with improved genotypes to harness the full benefits in the watershed. The integrated genetic and natural resource management (IGNRM) approach adopted in watersheds will thus make the grey to green revolution a reality